Core drill



Dec. 28 1926.

J. S. MITCHELL .CORE DRILL.

Filed July ll. 1924 mechanism more fully appear.

Patented Dec.' 23.1926.

UNITED STATES' PATENT OFFICE.

JOSEPH S. MITCHELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO- SULLIVAN MACHINERY COMPANY, A CORPORATION '0E MASSACHUSETTS.

conn

DRILL.

My invention relates to core drills.

'. Wedge members 9 inthe resilient member 8 a An object of my invention is to provide short distance below the upper edge thereof an improved core drilland relates es eciall to unproved core lifter mechanism or suc to provide an improved core drill having an improved core lifter mechanism having improved means for the passage of tluld to the drill bit. Still another object of my invention is to rovide an improved core lifter aving great flexibility and strength provided with improved .means formed therein for the-passage of mud fluid to the drill bit. lThese and other objects and advantages ofmy invention will hereinafter In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume practice.

In these drawings,' Fig. .1 is a central longitudinal sectional view through a core barrel and drill bit in which my improved core lifter mechanism is incorporated. 1

l Fig'. 2 is a transverse sectional view taken substantially on line 2-2 of Fig. 1; c

F ig."'3 is a detail vertical sectional view :taken substantially on line 3-3 of Fig.'2.

which permit the passage of the mud fluid from the interior of the core barrel 1 latera drill. Another object of my invention is ally through lthe apertures 14 around the exterior of the core lifter and downwardly to the cutting edges of the drill bit 7, the

mud fluid then, the 'core barrel c thebit and from t In the use of mechanism it will passing upwardly around caring the cuttings from he hole. v

be noted that during the drilling operation 'the core y13 passes upwardly through the core lifter into the-core barrel. During t of the core lifter his operation the bottom tends to cling to the core landis forced upwardly against the bottom `edge of the core barrel, cutting olf the flow of iuid over the top of the core lifter. When the inner lower surfaces of the wedges are worn down, the core 13 obstructs the passage of Huid between: the wedges at their lower ends consequently preventing theA mud fluid from passing through 'the s aces between the wedges, the ilu bit through the apertures 14, there being id then passing to the drill ample clearance between'the wedges at the top of the lifter.

If the apertures 14 were 'In this illustratlve form of my invention I omitted, a'heavy pressure would build up in the core barrel, forcing the core lifter downhave shown acorejbarrel 1 threadedly secured-as `at 2 at its lower end to a core lifter core-'lifter casing. 3- is threadedly^ secured at` through the core lifter even `when worn.

' As a result-of Amy improvement itwill be L bore 4"lin which my im roved core lifter,

generally designated 5, is disposed to be hereinafter described. The lower en of the its lower end as at 6' to a. drill bit 7 herein of the welll known rotary diamond type.

The core lifter 5 comprises a split resilient sheet metal spring member 8 of conical we ge-shape'd vcore engaging members 9 are suitably secured, hereln:v by rivets 10. The wedge members 9 are prov1ded with concave vertical inner surfaces 11 and at their lower ends with outwardlyvinclined. surfaces 12 which are ada ted tol direct and: guide a core '13 upwardly t rough the corelifter into the core barrel 1 in the usual manner. The spaces:Vv between the wedges permit the passage of mud Huid or the like to the 7drill bit.

In ny'improved construction it will be observed that 'a plurality of 4radially spaced apertures 14 are provided intermediate ,the

ward, practically cuttlng off the suppl of noted that a core lifter of improved form is providedhaving great elasticity Aand dstrength and improved means for ting the free passage of mud lui ermit-4 even whenin a worn condition, to the drill bit. It will also be noted that the core lifter may be applied" to core drills of aI standard form with a minimum of change.

While I have in .this application specifically'described one form which my invention may assume in stood that-this ractice, it will be underf rm of the same is shownl for purposes of illustration and that the invention may befmodified and embodied in various other forms withoutdeparting from dts, spirit or the claims.

y scope vof the appended What Iclalm as new and desire to secure by Letters Patent is:

l. Al core lifter mechanism comprising a resilient core lifter member having spaced radially projecting wedge shaped portions,

.. and means for permitting the lateral passage of fluid therethrough comprising radial openings formed in said member intermediate said portions 2. A core lifter mechanism comprising spaced wedge shaped core engaging elements,y a resilient member connecting said elements, and 'means for permitting the lateral passage of fluid therethrough comprising radial openings formed in said -meinber intermediate said elements.

. 3.A core lifter mechanism comprising a resilient spring member, spaced wedge shaped core engaging portions projecting inwardly therefrom, and means for permitting the lateral passage `of fluid therethrough comprising radial openings formed in said spring member intermediate said pontions. e

4. A core lifter mechanism comprising a resilient member, spacedwedge shaped core engaging members secured thereto, and means for permitting the passage of fluid laterally therethrough comprising 4radial wiener through said spring comprising radial openings formed in said spring intermediate said element.

8. A core lifter mechanism comprising an annular split spring of truncated conical form, a plurality 'of spaced inwardly projecting core engaging elements secured thereto, and means for permitting the lateral passage of Huid through said spring comprising radial openings formed in said spring intermediate said elements.

9. A core lifter mechanism comprising a resilient. spring member, spaced core engaging portions projectingl inwardly therefrom, and means for permitting the lateral passage of fluid through said spring comprising radial openings formed in said spring adjacent the upper'edge thereof and intermediate said core engaging portions.-

10. In a core drilling mechanism, 'a corebarrel, a drill bit carried thereby, a resilient corel lifter comprising a split spring member and` spaced inwardly proJecting core (ifi engaging portions thereon, and means for permitting the passage of' fluid from said barrel laterally through said lifter to said bit comprising radial openings in said spring p member intermediate said spaced core engaging portions.

In testimony whereof I airix my signature.

JOSEPH s. MITCHELL. 

